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Where to Begin? Right
Now!
The genetic analysis shown indicates that
human ancestors migrated out of
Africa three times in the last 1.7 million
years.
There’s LOTS of Extinct Primates that Came Before Us! This isn’t
even a complete diagram! There are
several identified
fossil species
missing – and there’s still over a
dozen ancient
hominids shown!
Modern Homo Species: from 1.7 MYA to today
• Genus of “modern” humans includes
• H. sapiens, • H. neanderthalensis
(neanderthals)• And several others,
including…
Homo erectus • H. erectus is the
species of Homo that originated in Africa and went on to populate the rest of the world, using fire and stone technology. We are their direct descendents.
“Archaic” Homo Species: ~2.8 to 1.7 MYA
• All were located exclusively in Africa
• Includes some australopithicus species, Homo habilis, and others.
The “Erects” – Our ancient ancestors on 2 legs. From ~ 5 MYA to ~2.8 MYA
• This is where arguments really get going as to who our “direct” ancestor species was.
• “Lucy” (3 MYA) is among these ancient homonids.
The Split with other Primate LinesBetween 5 and 7 MYA
• Somewhere in Africa there was a single population of primate that gave rise to all of the species we just spoke of.
• This population was definetly a “gracile” ape.
• Little is known about the very earliest human ancestors because, as you might expect…
Just Remember – There’s Lots of Hominids in Earth’s History
Homo sapiens are just the newest design of a 2-legged primate model that arose millions of years ago. It’s our brains that set
us apart from all of the rest.
Perspective: 10,000 years = 104 years
• Imagine all of the time that has passed since the most ancient civilizations beginning in Egypt and Mesopotamia
• Every civilization there ever was… every king, every queen, every nation or people… all arose in this time
Multiply by 6 = 60,000 Years
• 60,000 years ago is the “great leap” to complex social organization, as indicated by early art and ceremony
Multiply BY 100!
• Think of every generation of people that has come and gone since our ancestors first figured out how to draw a picture on a wall.
• No try to imagine that all happening 100 times…
• That’s 6,000,000 years – when we split from the ape line.
30,000 generations
• That’s what separates us from our common ancestor with chimpanzees.
• Even if every generation was only a day long, that would still be over 80 years!!!
30,000 generations = 2 years in prokaryotes
• Prokaryotes are the easiest way to study evolution because some of them reproduce every 30 minutes…
• A prokaryote population can evolve as much (or more) in 2 years than humans have in 6,000,000.
“Ida” Darwinius massilae: 47 MYA
• Not a human ancestor.• Oldest known primate fossil.
• Gives clues as to what the first primate ancestors might have been like.
Mammals• Mammal species over
65,000,000 years old are all similar in structure to small rats, mice, or shrews of today
Tree Shrew:Living organism most similar to the extinct common ancestor of all primates
Animals Evolve: ~600 MYA• Between 550
and 140 MYA, all of the common plant and animal phyla around today evolved.
Eukaryote evolution: Plants, Animals, and Microbes, oh my!
Animals
Unicellular groups
Plants
Fungi
Amoebas
Unicellular groups
3.7 Billion years ago – the first cells
• This is where biology begins. Before this, it’s all geology / astronomy / physics…
Birth of the Universe: The Big Bang
• What: Quantum singularity spontaneously transforms into pure energy.
• When: 13.7 x 109 years ago (BYA)• Why it’s Important: Everything, including all
space, time, matter, and energy in the Universe begins.
Formation of the Milky Way
• What: This is what our galaxy looks like when viewed from Earth, looking towards its center. There are about 2 x 1011 stars in it.
• There are billions of other galaxies in the Universe.
Milky Way from Above
• What: This is what our galaxy probably looks like when viewed from above.
• When: The oldest stars in the galaxy are about 13.2 x 109 years old.
The Solar System and Sun
• What: A protoplanetary disk that will become the Sun and planets condenses due to gravity in a molecular cloud of gas and dust.
• When: About 4.6 x 109 years ago.